I found 2 oddities in 10.7 binding as well, but also a solution that pulled down all the settings I wanted for Directory Utility.
If the BIND item is added to a 10.7 based configuration in Casper Admin and I leave Casper to take care of everything then BOTH the gidNumber mappings are enabled when only one should be. Also I think the directory location was set to afp: instead of smb: but I don't remember for sure.
Also, be sure you are not setting any Bind settings in a configuration profile as I found that it wiped out all settings completely if both were done. The machine was bound but all the options in Directory Utility were set to the defaults.
Solution:
Go back to the old method of having my personal bootscript actually call a policy whose only function is adding the very same BIND mentioned in #1 above via Accounts tab.
Down at the very bottom I simply have a line that says
jamf policy -trigger adbind
This has worked flawlessly for me everytime (provided you aren't playing around with profies and accidently set Directory stuff in there again). ;)